1. Field of the Invention
The present invention relates to seats for a vehicle. More particularly, the present invention relates to seats of a vehicle that have a massaging function.
2. Description of the Related Art
A seat of a vehicle having a massaging mechanism is already known. Such a seat (a power seat) is taught, for example, by Japanese Laid-Open Utility Model Publication No. 63-46136.
In the known power seat, the massaging mechanism has a plurality of vibrating devices (hummers) that are provided to a cushion pad of a seat back. Typically, the vibrating devices are movably disposed within a plurality through holes formed in the cushion pad and are coupled to a drive unit having a drive motor.
The vibrating devices thus disposed can be driven by the drive motor so as to discontinuously push the back of a passenger, thereby providing a massaging function for the passenger. As a result, the power seat thus constructed may provide the passenger with a relaxing effect.
However, in the power seat thus constructed, the vibrating devices are typically formed from rigid elastic materials such as hard rubber. Generally, such vibrating devices cannot be easily deformed or contracted when subjected to a compression force. Therefore, the vibrating devices may sometimes provide strong discomfort to the back of the passenger when the passenger is sitting on the seat while the vibrating devices are not operated, in particular, when the passenger is relatively firmly pressed toward the seat back due to the rocking motion or vibration of the moving vehicle.
Further, a different type of massaging mechanism is also known. Such a massaging mechanism is taught, for example, by Japanese Laid-Open Patent Publication No. 10-201804. The massaging mechanism taught by No. 10-201804 is intended to be used for a general massaging device. This massaging mechanism has a plurality of massaging elements each having an air bag that can be inflated or deflated by air supply and discharge.
It is considered that such a pneumatically movable massaging mechanism can be used for a vehicle seat. If the pneumatically movable massaging mechanism is combined with the vehicle seat (i.e., if in the power seat taught by No. 63-46136, the massaging mechanism utilizing the vibrating devices is replaced with the massaging mechanism taught by No. 10-201804), it is expected that the above described disadvantage can be overcome.
However, the pneumatically movable massaging mechanism may require complicated piping, correspondingly many fittings, or other such members. Therefore, labor-intensive and time consuming work is required to manufacture a power seat having such a massaging mechanism. This may lead to an increased manufacturing cost.